Draw-off control device for liquids



Feb. 16, 1932. J. H. GRIFFIN 1,344,955

v DRAW-OFF CONTROL DEVICE FOR LIQUIDS Filed March 14, 1931 Patented Feb;16 1932 UNETED STATES PATENT OFFICE JAMES HARRIS GRIFFIN, OF ST. HELENS,ENGLAND, .ASSIGNOR TO PILKINGTON BROTHERS LIMITED, OF LIVERPOOL,ENGLAND, A LIMITED LIABILITY COMPANY OF GREAT BRITAIN DRAW-OFF CONTROLDEVICE FOR LIQUIDS Application filed March 14, 1931, Serial No. 522,594,and in GreatBritain- March 21, 1930.

This invention relates to draw-oif control devices for liquids whichhave to be continually agitated such as those containing solid matter.in suspension and has for its object an improved draw-off control devicewhich does not become clogged by solid or coagulated matter.

According to the invention an air jet in the body of the device isdirected against the passage leading from the liquid supply pipe towardsthe discharge orifice and operates to prevent the flow of liquid throughthe said passage and at the same time keeps the passage free of solid orcoagulated matter.

I he drawings shown in section, in Figures 1 and 2, two alternativeforms of draw-ofir control devices for liquids made according to theinvention and attached to a liquid supply pipe 1. V i

he same reference figures apply to like or corresponding partsrepresented in Fig ures 1 and 2. A passage 2 in the valve body 3 leadsthe liquid from the supply pipe 1 toward the discharge orifice 4. A pipe5, connected witha supply of air under pres sure, terminates withinthevalve body 3 in a nozzle 6 which is directed toward the passa e 2.

accumulation of solid matter in the supply pipe 1 is prevented bymaintaining the liquid therein in circulation.

The jet of air issuing from nozzle 6 prevents the flow of liquid fromthe supply pipe 1 into the passage 2 and keeps the passage free of anyaccumulation of solid matter.

On stopping the supply of air to the nozzle 6, the liquid is free toflow through the passage 2 and out of the discharge orifice 4,

hese parts being so constructed that there is no passage n which thehquidcan remain stationary.

Having described my invention, Ideclare that what I claim and desire tosecure by end of the passage, the flow of liquid from said dischargepassage adapted to be prevented by a jet of air flowing from saidnozzle. I

2. In a draw-off control device for liquids the combination of a supplypipe in which the liquid isadapted to be maintained in circulation, adischarge passage therefromand a nozzle aligned with the dischargepassage to direct an air jet against the surface of the liquid in thedischarge passage.

In a draw-off control device for liquids JAMES'HARRIS GRIFFIN.

